A uniform resource locator (URL) is a unique identifier for accessing a network resource, such as a website. In general practice, a URL has two parts: a scheme and an address. These may be separated by a colon and two forward slashes. For example, the URL “http://www.uspto.gov” includes the scheme “http,” meaning that the resource is accessed via the hypertext transfer protocol (HTTP). The resource is the subdomain “www” on the domain “uspto” within the “gov” top-level domain (TLD), which is reserved primarily for U.S. government agencies.
URLs may also include a path within the domain or subdomain. For example, the URL http://www.uspto.gov/patents-application-process/file-online points to the path “patents-application-process/file-online on the www.uspto.gov server.